According to WebMD, multiple personality disorder, or dissociative identity disorder, cannot be cured. However, treatment has been very effective with patients who are dedicated to the long-term process.
The Cleveland Clinic indicates that, with dissociative identity disorder (DID), at least two distinct identities are able to control an individual's behavior at different times. Several treatments are available for this mental illness, and most patients use a combination of approaches. Medication is often prescribed. Drugs address problems that accompany DID, such as depression and anxiety, but do not directly deal with different personalities. Clinical hypnosis helps patients explore their subconscious for clues to the disorder. In addition, several forms of therapy are available, including psychotherapy and cognitive, family, art and music therapy.